Biopsy anchor device with cutter

ABSTRACT

A device for accessing and for isolating a desired site within a patient&#39;s body, and for obtaining a body of tissue from a patient at the site that includes an electrosurgical cutting electrode near the distal tip of a shaft, an anchoring mechanism and an electrosurgical side-cutting device. Methods are provided for accessing a target site within a patient&#39;s body, anchoring a body of tissue at the site, and isolating the body of tissue at the site. The method may be performed for a surgical biopsy or lumpectomy at the target site within a patient&#39;s body.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present invention is a continuation of U.S. patent application Ser.No. 09/753,529 for “Biopsy Anchor Device with Cutter,” filed on Dec. 28,2000 now U.S. Pat. No. 6,540,695, and a continuation-in-part of U.S.patent applications Ser. No. 09/057,303 for “Breast Biopsy System andMethod,” filed on Apr. 8, 1998, now U.S. Pat. No. 6,331,166; Ser. No.09/146,185 for “Methods and Apparatus for Securing Medical Instrumentsto Desired Locations in a Patient's Body,” filed on Sep. 1, 1998 nowU.S. Pat. No. 6,540,693; Ser. No. 09/159,467 for “Electrosurgical BiopsyDevice and Method,” filed on Sep. 23, 1998, now U.S. Pat. No. 6,261,241;Ser. No. 09/238,965 for “Tissue Specimen Destruction Device and MethodThereof,” filed on Jan. 27, 1999 now U.S. Pat. No. 6,659,105; Ser. No.09/356,187 for “Electrosurgical Lesion Location Device,” filed on Jul.16, 1999, now U.S. Pat. No. 6,312,429; and Ser. No. 09/477,255 for“Apparatus and Method for Accessing a Biopsy Site,” filed on Jan. 4,2000 now U.S. Pat. No. 6,471,700, all assigned to the assignee of thesubject application, which are each hereby incorporated by reference intheir entirety, and from each of which priority is claimed under 35U.S.C. 120.

FIELD OF THE INVENTION

The present invention relates generally to the field of surgical biopsyinstruments and methods. More specifically, it relates to devices andmethods for electrosurgically accessing a pathologically suspect tissuemass within a patient's body, anchoring the device relative to thesuspect tissue, and cutting tissue so as to isolate the suspect tissueand to facilitate the taking of a biopsy sample of the tissue mass, aswell as to facilitate subsequent surgical procedures in the region ofthe tissue mass.

BACKGROUND OF THE INVENTION

In diagnosing and treating certain medical conditions, such aspotentially cancerous tumors, it may be desirable to perform a biopsy,in which a specimen of the suspicious tissue is removed for pathologicalexamination and analysis. In many instances, the suspicious tissue islocated at a subcutaneous site, such as inside a human breast. Tominimize surgical intrusion into a patient's body, it is desirable to beable to insert a small instrument into the body to gain access to thedesired location for inspection and for extraction of a biopsy specimen.

Body tissue is often deformable, so that insertion of a needle or otherdevice into a patient's tissues will often deform or displace the tissuethrough which the needle or other device moves. Tissues of interest,such as nodules, masses, tumors and the like, which are typically thedesired targets of a biopsy sample, may be readily displaced, pushedaside or otherwise deformed during biopsy procedures, making it likelythat some or all of the desired target tissue may be missed during thebiopsy procedure, thereby increasing the likelihood of misdiagnosis ofthe condition that led to the need for the biopsy.

In extraction of a biopsy specimen with a probe, it may be desirable toanchor the probe in a desired position so as to insure that the proberemains in a proper position relative to the suspect tissue duringmanipulations and activities before and during the actual acquisition ofthe biopsy sample. In addition, it may be desirable to isolate tissuefrom neighboring healthy tissue in order to ensure that no diseased orabnormal tissue remains outside the sampled volume. Thus, the volume oftissue isolated may be larger than the minimum necessary so as to obtainmargins of tissue free of disease for pathological diagnosis.

Electrosurgical techniques have been used in a variety of circumstances,including certain types of biopsy procedures. In electrosurgery, highfrequency electrical energy is applied through a primary electrode topatient tissue. The electrical energy flows through the tissue to areturn electrode that is in contact with the patent's tissue. Typically,the return electrode is attached to the patient at a point remote fromwhere the primary electrode contacts the tissue. The tissue adjacent theprimary electrode is ablated, to form an opening in the tissue.

When electrically activated, the electrode ablates the tissue adjacentthe electrode, to produce a tissue opening which provides access totissue to be taken in a biopsy sample. Guidance of the electrode tip tothe desired site within a patient's body may be through stereotactic,radiological, ultrasonic, magnetic resonance imaging (MRI), or othermeans. However, there is frequently a delay between the positioning ofthe device and the taking of the biopsy sample, so that the device ortissue may move and prevent acquisition of the desired tissue.Accordingly, there is need in the art for means to mark a target sitewithin a patient's body and for means to anchor the biopsy device in aproper location.

The tissue to be sampled or removed from the patient will often comprisea volume larger than the volume of the biopsy probe to obtaindisease-free margins for pathological diagnosis. Accordingly, means forobtaining tissue samples larger than the probe itself are desired. Inaddition, it is of clinical interest to determine the extent of adiseased or abnormal portion of the tissue, and it is often desired thata border of normal tissue, surrounding any abnormal tissue present, beremoved as well. It is further desired that the tissue to be removed beisolated from the body to prevent migration of diseased or abnormaltissue into other locations of the patient's body.

Accordingly, there is need in the art for devices and methods foraccessing a desired site within a patient's body without displacingtarget body tissue, for anchoring devices at a desired site to preventmovement of such devices after arrival at a desired site, for isolatingtissue, and for taking biopsy specimens from a patient.

SUMMARY OF THE INVENTION

The present invention is directed to systems, devices and methods foraccessing target tissue within a patient, for isolating a body of targettissue from its supporting bed, for performing a lumpectomy, forperforming a biopsy, and for obtaining biopsy tissue. Accordingly, thepresent invention provides systems, devices and methods providing accessto a desired subcutaneous site for target tissue within a patient's bodyand for isolating such target tissue from a supporting tissue bed.

In one embodiment, a device having features of the invention has anelongated shaft having a distal end, a proximal end and a longitudinalaxis. An electrosurgical electrode is secured to the distal end of theshaft with a first electrical conductor extending within the shafthaving a distal end electrically connected to the electrosurgicalelectrode and a proximal end configured to be electrically connected toa high frequency electrical power source. An anchoring mechanism islocated proximal to the distal end; and a side-cutting mechanism havinga cutting element configured to be rotated about the longitudinal axisof the shaft and thereby isolate a body of target tissue.

In another embodiment, the invention is a biopsy device for obtainingtarget tissue within a patient. In such an embodiment, it has anelongated shaft that has distal and proximal ends and a longitudinalaxis; with an electrosurgical electrode secured to the distal end of theshaft. A device of this embodiment also has an electrical conductorextending within the shaft that is electrically connected at oppositeends to the electrosurgical electrode and to an electrical power source.The device also has an anchoring mechanism and a side-cutting mechanismhaving a cutting element. The cutting element is configured to berotated about the longitudinal axis of the shaft and so to isolate abody of target tissue.

In yet a further embodiment, the invention is a device for performing alumpectomy in a patient's breast. It has an elongated shaft with anelectrosurgical electrode secured to the distal end of the shaft and anelectrical conductor extending within the shaft that is electricallyconnected to the electrosurgical electrode and to an electrical powersource. The device of this embodiment has an anchoring mechanism locatedand a side-tufting mechanism having a cutting element that can berotated about the longitudinal axis of the shaft to isolate a body oftarget tissue for removal.

In another embodiment, the invention provides a method for accessingtarget tissue at a desired site within a patient and isolating a body oftarget tissue. This method includes the steps of providing a device ofthe invention, contacting a patient's body with the device, andsupplying high frequency electrical current to the electrosurgicalelectrode while advancing the device into the patient and through thesite of target tissue. The method also includes steps of an anchoringmechanism to penetrate the surface of the target tissue in order to fixthe device at the target tissue site. In addition, the method providesfor expanding the cutting element of the side-cutting mechanism into thetarget tissue and rotating the cutting element to cut a body of targettissue.

In a further embodiment, the invention provides methods for performing abiopsy on target tissue at a desired site within a patient, and ofperforming a lumpectomy on a breast of a patient. The methods includeproviding a device of the invention, positioning the electrosurgicalelectrode of the device in contact with the patient's body, supplyinghigh frequency electrical current to the electrosurgical electrode whileadvancing at least a portion of the shaft through the site of targettissue, expanding an anchoring mechanism to fix the device at the targettissue site, expanding the cutting element of the side-cuttingmechanism, rotating the cutting element to form a body of target tissue,and withdrawing the device with the body of target tissue from thepatient.

In one embodiment, the device of the invention has an elongated shaftwith an electrosurgical electrode effective to cut through tissue and toprovide access to target tissue within a patient's body. Theelectrosurgical electrode is configured to be electrically connected toan electrical power source. An anchoring mechanism is provided to engagethe target tissue and thereby anchor the device with respect to suchtarget tissue A side-cutting mechanism is configured to cut a body oftarget tissue so as to isolate the target tissue from its supportingbed.

In one presently preferred embodiment the side-cutting mechanismincludes an elongated electrode oriented along the elongated shaft withone end distal to the anchoring mechanism and one end proximal to theanchoring mechanism. In this fashion the elongated electrode can isolatethe target tissue. An electrical conductor extends within the elongatedshaft of the device to connect to the elongated electrode of theside-cutting mechanism to an electrical power source. Preferably, asingle electrical power source powers both the electrosurgical electrodeand the elongated electrode of the side-cutting mechanism although thecurrent frequency and power requirements may be different for the twoelectrodes.

The anchoring mechanism is an elongated member or preferably a pluralityof elongated members such as wires or ribbons which can be advancedgenerally radially away from the elongated shaft into the body of targettissue to fix the location of the device with respect to the targettissue. The elongated members should be curved outwardly to engage thesurface of the target tissue. To facilitate entry of the elongatedmembers into the body of target tissue, in a preferred embodiment thetips are sharp. In other embodiments, the elongated members may beformed of electrically conductive material and high frequency electricalcurrent may be applied to the elongated members. Facilitating entry ofthe elongated members into tissue eliminates the tenting effects whichmay occur when the tip of an elongated member contacts the surface ofthe target tissue and applies pressure thereto. The elongated members ofthe anchoring mechanism preferably should be movably mounted to theelongated shaft, so that they may be in a retracted configuration whenthe device is advanced through the patient's tissue or when the deviceis rotated to cut and isolate a body of target tissue, and may beextended generally radially to an expanded configuration to engage thetarget tissue as desired, before cutting and isolation of a body oftarget tissue and after such cutting and isolation.

The electrical power source is preferably a high frequency, e.g. a radioa frequency (RF), electrical power source. The frequency of the currentdirected to the elongated electrode of the side-cutting mechanism maybe, and is preferably greater than the frequency of the current directedto the electrosurgical electrode on the distal end of the elongatedshaft and the elongated members of the anchoring mechanism. Forobtaining a biopsy from soft tissue such a breast tissue the electricalenergy is provided in a frequency range of about 0.1 MHz to about 10MHz. In one presently preferred embodiment, the electrical energy isprovided to the electrosurgical electrode or the anchoring mechanism, orboth, in a frequency range of about 0.3 to about 1.5 MHz, preferablyabout 0.8 MHz. In another presently preferred embodiment, the electricalenergy is provided to the elongated electrode of the side-cuttingmechanism in a frequency range of about 0.5 to about 10 MHz, preferablyabout 2.5 to about 7.5 MHz, typically about 5 MHz.

A biopsy entails removal of diseased tissue, as in a lumpectomy. Abiopsy may be performed using the device of the invention by directinghigh frequency electrical current to the electrosurgical electrode onthe distal end of the device while pressing the electrosurgicalelectrode of the device into the patient's tissue. The electrosurgicalelectrode and the distal end of the device to which it is securedreadily passes through the tissue, making a cut therethrough with littleor no heat affected zone at the cut surfaces of the tissue through whichthe device passes. The distal end of the device may be guided throughthe patient's tissue by an imaging system such as an ultrasonic or x-rayimaging system until the anchoring and side-cutting mechanisms are at adesired location within the target tissue. The elongated members of thepreferred anchoring mechanism are then advanced out of their contractedconfiguration so that the distal ends thereof penetrate into the targettissue. The passage of the distal ends of the elongated members isgreatly facilitated by directing high frequency electrical currentthrough the members. The anchoring elements of the anchoring mechanismin their expanded configuration fix the device with respect to thetarget tissue.

The device is now ready to cut a body of tissue from the desiredlocation. To do this, the elongated electrode of the side-cuttingmechanism, preferably an arcuate electrode, is expanded outwardly whiledirecting high frequency electrical current through the electrode makinga longitudinal radial cut through the target tissue. In a preferredembodiment, the elements of the anchoring mechanism are then retracted,that is, replaced within or along the elongated shaft so that they areno longer in their deployed configuration, after the side-cuttingelectrode is deployed but before the side-cutting has begun cutting themargins of the tissue to be removed. At this point, preferably with theanchoring mechanism retracted, the expanded side-cutting electrode isthen rotated about the longitudinal axis of the device while highfrequency current is supplied thereto to separate and isolate a body oftarget tissue. In a preferred embodiment, the expanded side-cuttingelectrode rotates completely around the longitudinal axis of the device.In a most preferred embodiment, the expanded side-cutting electroderotates more than 360°, preferably 360° plus about an additional 45°,thus insuring that a body of target tissue is entirely isolated from itssupporting bed of body tissue, and that the final position of theside-cutting electrode is not directly over the slot created in thetissue as the side-cutting electrode expands outwardly duringdeployment.

The resulting separated and isolated body of target tissue issubstantially in the shape of a spheroid, where a spheroid is a roundedshape generated by revolving a shape around an axis. By substantially inthe shape of a spheroid is meant that the shape approximates a spheroid,and so is, e.g., roughly spherical, or elliptical, but may have anirregular shape that only generally approximates a spheroid. Forexample, the shape of the isolated body of tissue may be roughlycylindrical or conical.

The side-cutting electrode is thus effective to cut and isolate a bodyof tissue. Following separation and isolation of the a body of targettissue, the elements of the anchoring mechanism may be redeployed, andthe device may then be removed from the body of the patient along withthe isolated body of target tissue fixed by the anchoring members. Inpreferred embodiments, the side-cutting electrode, without beingsupplied with RF power, is partly retracted to aid in anchoring theisolated body of target tissue. A specimen substantially in the shape ofa spheroid, such as, e.g., a rounded, substantially spherical orelliptical specimen, containing target tissue isolated by an arcuatelyshaped electrode greatly simplifies the pathological examination of thespecimen both at its center and margins.

For removal of diseased tissue such as breast cancer, the size of thebody of target tissue to be removed is usually selected to besignificantly larger than the diseased tissue to ensure than all of thediseased tissue is removed. Where an isolated body of target tissue isfound to have healthy tissue surrounding more centrally-located diseasedtissue, a pathologist may more easily determine whether or not it islikely that any diseased tissue remains in the patient's body.

An advantage of the present invention is that it provides a roughlyspherical specimen of target tissue. A roughly spherical specimen iseasily examined to detect the presence and extent of diseased tissue. Ifthe tissue within the specimen is found to be in fact diseased, e.g. tocontain a carcinoma, then the entire surface of the roughly sphericalspecimen should be examined to be sure that there is no diseased tissueat the specimen margins. If the margins are free of diseased tissue,then the physician can be reasonably assured that all of the diseasedtissue has been removed. Alternatively, the presence of diseased tissueat the margins of the specimen suggests that additional diseased tissuemay remain within the patient's body.

After removing the target tissue samples or diseased tissues, additionalprocedures may be performed at the biopsy site or site of diseasedtissue. For example, it may be desirable to cauterize, coagulate orotherwise treat the resulting cavity to stop bleeding and reduce therisk of infection or other complications. Where tissue isolation isperformed, electrosurgical coagulation may be performed before or afterremoving the tissue specimen from the patient. Also, it may beadvantageous to mark the site for future surgical procedures shouldpathological tests performed on the biopsy specimen indicate surgicalremoval or other treatment of the suspected tissue mass from which thespecimen was removed. Such marking can be performed, for example, by theapparatus and method disclosed and claimed in co-pending U.S. patentapplication Ser. No. 09/343,975, filed Jun. 30, 1999, entitled “BiopsySite Marker and Process and Apparatus for Applying It,” which is herebyincorporated by reference in its entirety.

The devices and methods of the invention provide the advantage ofanchoring the device at a target location, avoiding movement after asite of interest has been identified within the body of a patient. Afurther advantage is provided by the ability of the device to cut a bodyof tissue from that correct location, without needing to position aseparate instrument at the site. In addition, the present inventionprovides a roughly spherical specimen of target tissue, which by itsshape is easily examined to detect the presence and extent of diseasedtissue.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of a tissue removing system illustratingfeatures of the invention.

FIG. 2A is a perspective view of a device with radial wires andside-cutting wire electrode retracted; FIG. 2B a perspective view of adevice with radial wires extended; FIG. 2C a perspective view of adevice with radial wires and side-cutting electrode extended; and FIG.2D a perspective view of a device with the side-cutting electrodeextended.

FIG. 3A a perspective view of a wand with radial wires and side-cuttingelectrode retracted; FIG. 3B a perspective view of a wand with radialwires and side-cutting electrode extended; FIG. 3C is a partiallycut-away view of a handle embodying features of the invention, showing aplunger mechanism embodying features of the invention with a plungerextended; and FIG. 3D is a partially cut-away view of a handle embodyingfeatures of the invention, showing a plunger mechanism embodyingfeatures of the invention with a plunger depressed.

FIG. 4A is a partly cut-away perspective view of the distal tip of thewand particularly showing an electrosurgical electrode. FIGS. 4B and 4Care perspective views of the distal portion of the wand showing extendedradial wires and an extended side-cutting electrode illustratingfeatures of the invention.

FIGS. 5A and 5C are longitudinal cross-sectional views of the shaft ofthe wand of FIG. 1 embodying features of the invention, and FIGS. 5B,and 5D-F are transverse cross-sectional views of the shaft of the wandof FIG. 1 embodying features of the invention.

FIGS. 6A and 6C are longitudinal cross-sectional views of the shaft ofthe wand of FIG. 1 embodying features of the invention, and FIGS. 6B and6D are transverse cross-sectional views of the shaft of the wandillustrating features of the invention showing a side-cutting electrodein retracted (6A, 6B) and extended (6C, 6D) configurations.

FIG. 7 is a perspective view of devices illustrating features of theinvention.

FIGS. 8A-8F provide partially cut-away perspective views of a surgeon'sdisposable unit illustrating features of the invention.

FIG. 9 is a cross-sectional view of a breast of a patient undergoing aclinical procedure embodying features of a method of the invention,showing a distal portion of a device embodying features of theinvention.

FIG. 10 provides partially cut-away side-views of the wand of FIG. 1embodying features of the invention and transverse cross-sectional viewsof the wand and breast tissue during a procedure embodying features ofthe methods of the invention. FIG. 10D is a partially cut-away side-viewof the wand. FIGS. 10A-10C are transverse cross-sectional views of thewand, FIGS. 10B and 10C also including transverse cross-sectional viewsof breast tissue, during a procedure embodying features of the methodsof the invention.

DETAILED DESCRIPTION OF THE INVENTION

In FIG. 1 and in all succeeding figures, like elements are indicated bylike numerals. Reference is made to FIG. 1, showing a system of theinvention 10 comprising an electrosurgical device, or wand, 110, asurgeon's disposable unit 120, and a motor unit 130. These devices maybe used to access target tissue within a patient, to isolate a body oftarget tissue from its supporting bed, to perform a biopsy on targettissue at a desired site within a patient, or to perform a lumpectomy ona breast of a patient. When assembled together, the devices form asystem for accessing tissue within a patient's body, including, invarious aspects, a biopsy system and a lumpectomy system. These systemsfurther comprise devices for anchoring tissue that has been accessed, orfor ablating tissue that has been accessed. A portion of wand 110 isillustrated in FIG. 1. The wand 110 comprises an electrosurgical devicethat includes a distal tip 12 situated at the distal portion 16 of ashaft 14. Situated near the distal tip 12 of the shaft 14 is anelectrosurgical electrode 18. Shaft 14 has a longitudinal axis 24 thatis effective to define a radial direction 26 perpendicular tolongitudinal axis 24. The anchoring mechanism may be comprised of anchorelements, such as metallic wires or ribbons, extending radially (thatis, extending at least in part in a radial direction 26) from shaft 14;similarly, the ablation mechanism may be comprised of ablation elements,such as metallic wires or ribbons, extending at least in part radiallyfrom shaft 14, the metallic wires or ribbons of an ablation mechanismpreferably being longer than those of an anchoring mechanism. Ananchoring mechanism may be capable of serving also as an ablationmechanism where it is used during rotary motion of the device or wheresufficient electrical power is conducted to the metallic ribbons orwires. The radial wires 20 shown in the Figures thus illustrate eitheran anchoring mechanism or an ablation mechanism or both. Radial wires 20emerge from radial wire slots 22 situated at a position proximal to thedistal tip 12 along shaft 14. Although the radial wires 20 are shown inFIG. 1 deployed in their extended configurations, it will be understoodthat they may also retract into slots 22 in their retractedconfiguration, as is shown in subsequent Figures.

The devices of the invention also comprise a side-cutting mechanism. Aside-cutting mechanism is illustrated in the Figures as side-cuttingelectrode 28, comprising an arcuate band or ribbon electrode whendeployed in its extended configuration. Thus, a side-cutting mechanismof the invention is shown in FIG. 1 as side-cutting electrode 28effective for cutting tissue and for isolating tissue in a patient.Side-cutting electrode 28 lies along shaft 14 when retracted and assumesan arcuate configuration when deployed (as, e.g., illustrated in FIG.1). However, it will be understood that in other embodiments of theinvention side-cutting electrode 28 may be provided with a slot intowhich it may be retracted.

Surgeon's disposable unit 120 is effective to engage and hold wand 110,and to work together with it. Both wand 110 and surgeon's disposableunit 120 are preferably sterile. In preferred embodiments, wand 110 andsurgeon's disposable unit 120 are not reusable, but are instead meant tobe used for one procedure only. Surgeon's disposable unit 120 isoperably connected to RF power source 34 and ground plate 36 via cableassembly 37, the cable assembly 37 comprising at least one conductoreffective to carry RF power. In preferred embodiments, cable 37 isconnected to RF power unit 34 via a plug-in connection, so thatsurgeon's disposable unit 120 and RF power unit 34 may be readilyconnected or disconnected as desired. In most preferred embodiments, thecable is adapted to provide for efficient transfer of RF power to thewand, by impedance matching, capacitance minimization, or other meansfor maximizing the efficiency of RF power transfer. Electrical contactbetween surgeon's disposable unit 120 and wand 110 when wand 110 isseated in and held by surgeon's disposable unit 120 is effective toprovide wand 110 with RF power from RF power source 34. Such RF powermay be supplied to electrosurgical electrode 18, to radial wires 20 andto side-cutting electrode 28 via at least one conductor in wand 110.Effective electrical contact between ground plate 36 and the patient isprovided during a clinical or surgical procedure by placement of groundplate 36 in contact with the patient. Electrical contact between groundplate 36 and a patient may be enhanced by application of conductive gelsor creams to the skin of the patient, and by other methods known tothose of ordinary skill in the art as well. Where the elements 18, 20and/or 28 are operably connected to a source of RF power 34, and where apatient is in contact with a ground plate 36 operably connected to asource of RF power 34, contacting a patient with an electrosurgicalelectrode 18, radial wire 20, and/or side-cutting electrode 28 iseffective to allow the passage of RF power between the element 18, 20and/or 28 and the patient, effective to allow RF cutting or penetrationby the elements 18, 20 and/or 28, as desired, effective to allow theelement to penetrate the patient's tissues. Where the element is aradial wire 20 that is an ablation element, such passage of RF power iseffective to ablate tissue in contact with the element. Where theelement is an electrosurgical electrode 18, a radial wire 20 that is ananchoring element, or a side-cutting electrode 28, such passage of RFpower is effective to cut the tissue, and optionally to coagulate thetissue as well. It will be understood that RF power source 34 maycomprise more than one source of RF power.

It will be understood that all electrical devices require a completeelectrical circuit to function. The complete circuit required for theproper functioning of an electrosurgical device may be either monopolaror bipolar; that is, the return electrical path may be to a groundelectrode distant from the point of delivery of electrical power, suchas RF power, or may be to a ground electrode near to or on the sameinstrument.

With a monopolar device, the return electrical path is provided througha ground electrode, such as ground pad 36. With a bipolar device, thereturn electrical path from the primary electrode (such as theelectrosurgical electrode 18, radial wires 20, or the side-cuttingelectrode 28) is provided by a return electrode carried on the sameinstrument, such as wand 110. In preferred embodiments, theelectrosurgical devices of the invention are monopolar electrosurgicaldevices.

In addition to providing operable electrical connection between wand 110and RF power source 34, surgeon's disposable unit 120 is effective toprovide or transfer mechanical force to wand 110 when wand 110 isengaged and held by surgeon's disposable unit 120.

Motor unit 130 provides mechanical force, such as rotary motion,effective to drive or rotate a shaft or shafts (e.g., co-axial shafts)operably connected to it. As illustrated in FIG. 1, motor unit 130 isoperably connected to surgeons' disposable unit 120 (which may comprisea shaft able to be operably connected to motor unit 130) and receivespower via power connection 39. It will be understood that motor unit 130could contain an electric motor or motors and power connection 39 couldcomprise an electrical cable; alternatively, motor unit 130 may compriseone or more hydraulic or pneumatic motors, and power connection 39 couldcomprise a conduit for hydraulic or pneumatic fluid or gas. It will beunderstood that motor unit 130, power connection 39, and associatedelements may be positioned and adapted in any suitable manner effectiveto provide motive force via motor unit 130 to surgeon's disposable unit120. Motor unit 130 can engage and work with surgeon's disposable unit120 effective to provide or transfer mechanical force to surgeon'sdisposable 120, which is itself effective to provide or transfermechanical force to wand 110 when wand 110 is engaged and held bysurgeon's disposable unit 120. Motor unit 130 is typically not a steriledevice, although it may be used in sterile procedures when routineprecautions known to those of ordinary skill in the art are taken. Forexample, motor unit 130 may be covered with a sterile cover or wrap,such as a sterile “sock,” for use in a sterile procedure with wand 110and surgeon's disposable unit 120.

Wand 110 comprises a shaft portion and a housing portion. As illustratedin FIG. 2, the shaft portion comprises shaft 14 and associated elements,such as electrosurgical electrode 18, radial wires 20, and side-cuttingelectrode 28, while the housing portion comprises housing 40 andassociated elements. A portion or portions of shaft 14 may be containedwithin housing 40. Elements associated with housing 40 include thoseelements contained within housing 40 that are also mounted on shaft 14,such as shaft gear 41, radial wire shuttles 42A and 42B, andside-cutting electrode shuttle 44. Shaft gear 41 is operably connectedto shaft 14, so that rotation of shaft gear 41 is effective to rotateshaft 14. Rotation of shaft 14 may be effected by the engagement ofshaft gear 41 with a suitable drive gear. In preferred embodiments, sucha drive gear is provided by drive gear 72 in surgeon's disposable unit120, shown in FIG. 8. It will be understood by those of ordinary skillin the art that there are many suitable ways to rotate portions of thedevice, or to rotate the entire device, and that any suitable mechanismfor effecting rotation of the device or of the elongated shaft, and inparticular, rotation of side-cutting electrode around the longitudinalaxis 24 of shaft 14 will be suitable for the practice of the invention.

In FIG. 2 the distal direction is shown to the left, towardselectrosurgical electrode 18 located at distal tip 12, and the proximaldirection is shown opposite the distal direction. Shuttles 42A, 42B, and44 are mounted along the shaft 14 within housing 40, and are effectiveto move proximally and distally in longitudinal directions alongportions of shaft 14 located within housing 40. Radial wire shuttles 42Aand 42B are operably connected to radial wires 20, and side-cuttingelectrode shuffle 44 is operably connected to side-cutting electrode 28.

As shown in FIGS. 2B and 2C, when radial wire shuttles 42A and 42B areseparated from each other, and are located in their most proximal anddistal positions, the radial wires 20 are deployed in their extendedconfigurations. Similarly, when side-cutting electrode shuttle 44 is inits most proximal position, as shown in FIGS. 2C and 2D, theside-cutting electrode 28 is deployed in its extended configuration. Asshown in FIG. 2A and 2D, when radial wire shuttles 42A and 42B arelocated adjacent to each other, the radial wires 20 are in theirretracted configuration. Similarly, when side-cutting electrode shuttle44 is in its most distal position, as shown in FIGS. 2A and 2B, theside-cutting electrode is in its retracted configuration.

Electrosurgical electrode 18 may be operably connected to a source of RFpower, such as 34 shown in FIG. 1. In preferred embodiments, suchconnection is via conductors in wand 110, operably connected toconductors in handle 46 connected to a source of RF power. Suchconductors may be, for example, conductor 60. In preferred embodiments,the source of RF power for electrosurgical electrode 18 is not the samesource of RF power for side-cutting electrode 28. In preferredembodiments, electrosurgical electrode 18 requires lower frequency RFpower than does side-cutting electrode 28. Contacting a patient with theelectrosurgical electrode 18 while the patient is in contact with aground plate 36 and electrosurgical electrode is supplied with RF powerallows an operator to penetrate a patient's body with device 110 byguiding the electrosurgical electrode 18 into the patient to accesstissue within a patient's body.

The wand 110 may be inserted into a patient's body to position thedistal tip 12 or shaft 14 at a desired site or a targeted tissue site(e.g., a suspected lesion or tumor) in the patient, thereby providingaccess to the targeted tissue site. In preferred embodiments, handle 46holds wand 110 as shaft 14 is inserted into position in a patient; inpreferred embodiments, handle 46 is also used to deploy anchor wires 20.In one embodiment, shaft 14 can have a length of about 3 to about 15 cm,preferably, about 5 to about 13 cm, and more preferably, about 9 toabout 11 cm.

To assist in properly locating the elongated shaft 14 during advancementof the wand 110 into a patient's body, (as described below), the shaft14 may be optionally provided with indicators 31. The tip 12, shaft 14and other supporting parts of device 110 may be made of any suitablematerial. In some embodiments, the tip, 12, elongated shaft 14 and otherparts of device 110 may be made of a sturdy, high impact biocompatiblematerial such as medical grade polymer (e.g., high density polyethylene(HDPE), polycarbonate, fluorocarbon polymers, such as fluorinatedethylene propylene (FEP) polymer, or other polymer known in the art). Inpreferred embodiments, shaft 14 comprises polycarbonate. In otherembodiments, the shaft 14 may be comprised of biocompatible polymertubing, such as polyethylene, polyimide, ether sulfone, polysulfone, orthe like. The shaft 14 may be optionally coated with a lubriciouscoating such as, for example, a Teflon® (polytetrafluoroethylene)coating, or other hydrophilic coating,

Shaft 14 may have, but need not have, a circular cross-section. In someembodiments, shaft 14 has an oval cross-section. Other cross-sectionalshapes are also suitable, including square, rectangular, triangular, andirregular cross-sectional shapes. In addition, the cross-sectional shapeand the width of shaft 14 may vary along its length. Accordingly, thewidth of shaft 14 may vary according to the position and method ofdetermining such width. However, one measure of the width, orcross-sectional dimension, of shaft 14 is a radial dimension extendingfrom one lateral surface to an opposite lateral surface of shaft 14taken along a line perpendicular to longitudinal axis 24. In oneembodiment, shaft 14 has a radial dimension of about 0.5 to about 20 mm,preferably of about 1 to about 10 mm, more preferably of about 1 toabout 5 mm. However, it will be understood by those of skill in the artthat suitable radial dimensions may vary, and may vary depending on thelocation or condition of the tissue to be sampled, so that suitableradial dimensions within the scope encompassed by the present inventioninclude radial dimensions greater than 10 mm and radial dimensionslesser than 1 mm.

The wand 110 has a distal tip 12 from which an electrosurgical electrode18 protrudes. The distal tip may comprise mica/glass composite, medicalgrade polymer as exemplified above, or other suitable material. Theelectrosurgical electrode 18 can be formed of conductive wire or ribbon.It will be understood that any biocompatible material, including steel,tungsten, nitinol, and other conductive biocompatible materials aresuitable to form an electrosurgical electrode 18. An electrosurgicalelectrode 18 may comprise conductive wire or ribbon of between about0.005 inches to about 0.030 inches in diameter, preferably between about0.01 inches to about 0.02 inches, more preferably about 0.014 inches indiameter. In preferred embodiments, the electrosurgical electrode ismade of stainless steel, such as 300 series or 17-7 stainless steel orequivalent, for example 302 stainless steel wire of approximately 0.014in. (approximately 0.36 mm) diameter. As shown in the Figures, a portionof the electrosurgical electrode may be semi-circularly shaped, althoughit will be understood by one of ordinary skill in the art that a varietyof shapes are suitable for the practice of the invention. Theelectrosurgical electrode 18 is in direct electrical contact with the RFpower source 34. When the electrosurgical electrode 18 is electricallyactivated with high frequency electrical energy and placed in contactwith tissue, electrical energy flows through the tissue to a returnelectrode (such as ground plate 36) that is also in contact with thepatient. The tissue adjacent the electrosurgical electrode 18 is ablatedto create an incision as the electrosurgical electrode 18 passes throughthe tissue. The electrosurgical electrode 18 can have a radius,subtending a maximum width approximately equal to or slightly greaterthan the maximum cross-sectional dimension of the elongated shaft 14, sothat during the electrosurgical process, the electrosurgical electrode18 makes an opening through the tissue sufficiently large to receive theelongated shaft 14. In a preferred embodiment of the invention, themaximum width of the electrosurgical electrode 18 is approximately 1.5times the maximum outside radial dimension of the elongated shaft 14. Inpreferred embodiments, the maximum width of the electrosurgicalelectrode 18 can be from about 2 to about 14 mm, preferably, about 4 toabout 12 mm, and more preferably, about 7 to about 9 mm. It will beunderstood by those of skill in the art that the electrosurgicalelectrode may be of any suitable size and shape effective to produce anincision to allow passage of the wand 110 through the patient's tissueto provide access to desired tissue within a patient and to provide forisolation of desired tissue within a patient.

Optional markings 31 along shaft 14 may be used to aid an operator ingauging the depth of penetration into a patient. In preferredembodiments, the operator is aided in the guidance of such penetrationby imaging apparatus and techniques such as ultrasound, x-ray imaging,magnetic resonance imaging, computer tomography, and other methods knownin the art.

The side-cutting electrode 28 may comprise an elongated electrode with adistal end, a proximal end and a middle portion. In a most preferredembodiment, a side-cutting electrode follows an arcuate path (as shownin FIGS. 1 and 2, and in subsequent figures) in a directionsubstantially parallel to a longitudinal axis 24 of the elongated shaft14. In the embodiment shown, the side-cutting electrode 28 thus lies ina plane substantially parallel to a radius 26 of the elongated shaft 14.It will be understood by those of skill in the art that the shapes ofside-cutting electrodes may differ from the arcuate shape illustrated inFIGS. 1 and 2. For example, suitable shapes of side-cutting electrodesinclude shapes with angles and straight portions as to well as smoothcurves. It will be understood that the side-cutting electrode iseffective to cut, ablate, coagulate and/or cauterize tissue whensupplied with RF power, and the patient placed in contact with a groundplate 36, similar to that described for the electrosurgical electrode18.

A side-cutting electrode 28 can be formed of conductive wire or ribbon,and may be made of any suitable material effective to conduct RF powerto tissues. It will be understood that any biocompatible material,including steel, tungsten, nitinol, and other conductive biocompatiblematerials are suitable to form a side-cutting electrode 28. In preferredembodiments side-cutting electrodes comprise metals such as tungsten,tungsten alloys, and stainless steel, for example 300 series or 17-7stainless steel or an equivalent. In most preferred embodiments, theside-cutting electrode 28 comprises tungsten. Side-cutting electrodesmay be, for example, about 0.001 to about 0.04 inches in diameter,preferably between about 0.005 and about 0.02 inches in diameter, mostpreferably about 0.01 inches in diameter.

In FIG. 1, radial wires 20 are shown extending in radial directions fromthe elongated shaft 14, while radial wires 20 are retracted in FIGS. 2Aand 2D. Thus, FIGS. 1 and 2 illustrate embodiments of the invention inwhich the radial wires 20 are mounted to shaft 14 effective to allowtheir deployment and retraction. In preferred embodiments, the radialwires may extend or retract from shaft 14 via radial wire slots 22 topositions of greater or lesser radial extension. Thus, in deploying, theradial wires are effective to expand outwardly from the elongated shaftof the device; when such expansion is effected after shaft 14 has beeninserted into a patient's tissues, and while shaft 14 remains within apatient's tissues, the expansion of the radial wires is effective topenetrate into a patient's tissue. In preferred embodiments, penetrationof radial wires 20 into a patient's tissues may be aided by sharpeningthe radial wire tips. Penetration of radial wires may also be aided bysupplying RF power to the radial wires. In embodiments comprising ananchoring mechanism, where the radial wires 20 comprise anchoringelements and where penetration is aided by supplying RF power to theradial wires, the radial wires 20 may comprise conductive material suchas a metal and may be insulated along their length except near to theirtips 56, which are conductive and not insulated. In preferredembodiments comprising an ablation mechanism where the radial wirescomprise ablation elements, the radial wires comprise conductivematerial, such as a metal, and may receive RF power.

In a contracted configuration, with the radial wires 20 withdrawn intoslots 22, the radial wires present no obstacle to movement of the shaftthrough a patient's tissues, such as advancement through, or rotationwithin, body tissue. When deployed in a radially expanded configuration,with RF power not connected to the radial wires 20, radial wires 20 areeffective to prevent movement of the shaft and of the device 110, and soto hold the device 110 in position. In a preferred embodiment, radialwires 20 are housed in shaft 14, are capable of emerging from shaft 14from radial wire slots 22, and optionally deploy to variable lengthoutside the shaft 14. It will be understood by those of skill in the artthat radial wires 20 may comprise a variety of shapes and lengths, thatany suitable means for attaching radial wires 20 to shaft 14, anysuitable means for housing the radial wires within shaft 14, and anysuitable means for extension of the radial wires into adjacent tissueeffective to anchor the wand 110 at a desired site within a patient areall within the scope of the invention. Such radial wires 20 may be, forexample, between about 0.003 inches to about 0.02 inches in diameter,preferably between about 0.05 inches to about 0.015 inches in diameter,more preferably about 0.009 in. (0.23 mm) in diameter. In preferredembodiments, radial wires 20 may be formed of 300 series stainlesssteel, 17-7 stainless steel or an equivalent. Radial wires 20 may bepartially coated with an insulating coating such as a polymer with highdielectric strength, for example, polyimide, so that only part of thewire, such as a part near the tip 56, is exposed and is able to passcurrent into surrounding tissue. In alternative embodiments, radialwires 20 may be modified so as to comprise an optical fiber capable ofproviding illumination, or hollow to allow deposition of dye or markersubstances, so as to facilitate visualization of the anchor elements.

The electrosurgical electrode 18, radial wires 20 and the side-cuttingelectrode 28 may be operably connected to an RF power source. Forexample, an electrical connection between side-cutting electrode 28 anda source of RF power may be comprised of Litz wire, preferably ofsuitable length to allow for the extension and rotation of side-cuttingelectrode 28. It will be understood by those of skill in the art thatany suitable electrical power source may be used. In use, where at leastone of the electrosurgical electrode 18 or radial wires 20 orside-cutting electrode 28 are monopolar electrodes, a portion of thepatient's body will be placed in contact with the ground plate 36 toprovide electrical continuity and a complete circuit. Alternatively,where the electrosurgical electrode 18 and side-cutting electrode 28 andanchor wires 20 are all bipolar electrodes, the ground plate 36 will beunnecessary for cutting, and may be omitted, with electrical continuityprovided by both of the poles of the bipolar electrodes or by a returnelectrode located near to the electrosurgical electrode 18, side-cuttingelectrode 28 and anchor wires 20.

As shown in FIG. 3, wand 110 may be inserted into tissue and anchored inplace using handle 46 as system 140. Wand 110 fits into notch 51 shownin FIG. 3A, and may be seated in and engaged by handle 46 so that wand110 may be carried and is guided by an operator for use in a biopsy orsurgical procedure. Handle 46 provides electrical connection betweenwand 110 and RF power unit 34 and ground 36 via cable assembly 37 andprovides mechanical control of radial wires 20 via the radial wireshuttles 42A and 42B. FIG. 3A shows wand 110 with the radial wires 20retracted, while FIG. 3B shows wand 110 with radial wires 20 deployed inthe extended configuration. Depression of plunger assembly 47 of handle46 is effective to deploy radial wires 20, as illustrated in FIG. 2B,while retraction of plunger assembly 47 is effective to retract radialwires 20, as illustrated in FIG. 3A. It will be appreciated that manymethods of effecting the deployment and retraction of radial wires 20are suitable for the practice of the invention, and all such are withinthe scope of the invention.

A preferred embodiment of handle 46 is illustrated in partially cut-awayviews in FIGS. 3C and 3D, showing manual shuttle clasps 50A and 50B andpivot assembly 52. Manual shuttle clasps 50A and 50B are effective toengage radial wire shuttles 42A and 42B when wand 110 is seated in notch51 of handle 46. Plunger 47 connects with plunger shaft 48 to provide anoperable connection to shuttle clasp 50A, shown in FIGS. 3C and 3D, sothat depression or retraction of plunger assembly 47 moves shuttle clasp50A effective to move pivot assembly 52 causing opposite motion ofshuttle clasp 50B.

FIG. 4 shows the distal portion 16 of shaft 14 in a perspective view.FIG. 4A shows the electrosurgical electrode 18 in greater detail,providing a view of the interior of the distal tip 12 of wand 110 whichallows a view of those portions of the electrosurgical electrode 18positioned inside the distal tip 12. The electrosurgical electrode 18 asshown in FIG. 4 is a loop of conductor, such as stainless steel, whichis operably connected to the distal end of conductor 60 providingelectrical connection with, for example, a source of RF power 34. FIG.4B illustrates the distal portion 16 of a shaft 14 of a device of theinvention with an anchoring mechanism comprising radial wires 20. FIG.4C illustrates the distal portion 16 of a shaft 14 of a device of theinvention with an ablation mechanism comprising radial wires 20. Notethat radial wires 20 shown comprising an ablation mechanism shown inFIG. 4C may be longer than the radial wires comprising an anchormechanism shown in FIG. 4B. Also shown is a side-cutting electrode 28and an electrosurgical electrode 18.

In their retracted configuration, shaft 14 of wand 110 houses theelements radial wires 20 (and may optionally house side-cuttingelectrode 28 where shaft 14 is provided with a side-cutting electrodeslot), provides electrical connection between these elements and RFpower source 34, and provides mechanical control effective to deploythese elements when it is desired to extend them outside slots 22 (andoptionally, a side-cutting electrode slot). FIG. 5 providescross-sectional views of the shaft 14 of wand 110 showing radial wires20 housed within slots 22, with tips 56 of radial wires 20 within slots22 in FIG. 5A (where radial wires 20 are shown in their retractedconfiguration) and extending out of slots 22 in FIG. 5C (where radialwires 20 are shown in their extended configuration). Transversecross-sectional views of a shaft 14 of a wand 110 of the invention areshown in FIGS. 5B, 5D, 5E and 5F.

Slots 22 are in part defined by slot material 62, whereby radial wires20 are able to slide within and exit from slots 22 during deployment.The radial wires 20 are shown retracted in FIGS. 5A, 5B and 5D-F. Radialwires 20 are operably connected to deployment shafts 58A and 58B, sothat longitudinal motion of 58A in one direction, and longitudinalmotion of 58B in the opposite direction, is effective to cause radialwires 20 to move within slots 22. As shown in FIG. 5C, longitudinalmotion of deployment shafts 58A and 58B carries radial wires 20effective to extend radial wires 20 out of slots 22. In preferredembodiments, anchor wires 20 have sharpened tips. In embodiments whereradial wires 20 are effective to conduct RF energy to body tissues whenthe radial wires 20 are deployed and in contact with body tissues,deployment shafts 58A and 58B comprise conductors effective to conductRF energy to radial wires 20. In embodiments, deployment shafts 58A and58B may be insulated; in addition, deployment shafts 58A and 58B maycomprise lubricating coatings or low-friction materials or coatings,such as may be provided by materials such as Teflon®. In most preferredembodiments, such insulation provides a low friction surface. Also shownin FIG. 5 is conductor 60, which extends within shaft 14 effective toprovide electrosurgical electrode 18 with RF power. In preferredembodiments, conductor 60 is insulated; most preferably conductor 60 isinsulated by insulation 61 effective to prevent electrical contact withdeployment shafts 58A or 58B.

FIG. 6 provides partly cut-away views of the shaft 14 of a wand 110 ofthe invention showing the side-cutting electrode 28 in its retracted(6A, 6B) configuration, and in an extended configuration (6C, 6D).Side-cutting electrode 28 contacts push bar 59, which is preferablysufficiently rigid to effectively transmit mechanical force, extendswithin shaft 14 to contact side-cutting electrode shuttle 44 withinhousing 40 of wand 110. Preferably, push bar 59 is rigid, notconductive, and effective to move and position side-cutting electrode28, while a conductor 32, separate from push bar 59, is used to supplyRF power to side-cutting electrode 28. For example, in preferredembodiments push bar 59 may comprise a polyester push bar 59 while aconductor 32, e.g., preferably comprising Litz wire, provides electricalconnection to side-cutting electrode 28. In alternative embodiments ofthe invention, push bar 59 is conductive effective to conduct RF energyto side-cutting electrode 28 without need for conductor 32. Longitudinalmotion of the side-cutting electrode shuttle 44, as shown by thedifferent positions of shuttle 44 in FIGS. 6A and 6C, is effective tourge push bar 59 and side-cutting electrode 28 in the same longitudinaldirection. However, longitudinal motion of the side-cutting electrode isconstrained by distal pivot 30, so that continued motion of side-cuttingelectrode shuttle 44 at one end, coupled with an inability for furtherlongitudinal movement of side-cutting electrode 28 at the opposite end,causes side-cutting electrode 28 to bulge and extend radially outward todeploy along an arcuate path as shown in FIG. 6C. The radial movement ofside-cutting electrode 28 is also shown, in transverse cross-sectionalviews, in FIGS. 6B and 6D. It will be understood by one of ordinaryskill in the art that other embodiments of a deployment mechanism forside-cutting electrode 28, and of push bar 59 and conductor 32connecting to side-cutting electrode 28, may be suitable for thepractice of this invention. For example, in some embodimentsside-cutting electrode 28 and push bar 59 may comprise a singlecontinuous unit. In other embodiments, side-cutting electrode 28 iscomprised of a memory metal, such as nitinol, effective to aid in thedeployment of side-cutting electrode 28 upon provision of conditionstriggering shape change in the memory metal.

Conductor 32 and conductor 60 (and, optionally, deployment shafts 58Aand 58B and push bar 59) comprise conductors which run along alongitudinal axis of shaft 14 to provide electrical connection between asource of RF power 34 and the electrosurgical electrode 18 at the distaltip 12 of shaft 14, the side-cutting electrode 28 and optionally theradial wires 20. These electrical conductors operably connect to asource of electrical power, such as RF power source 34, of a typecommonly used in electrosurgery. In preferred embodiments, theelectrical conductors are insulated to maintain electrical isolationfrom adjacent components. For example, conductor 60 may be covered orenclosed by insulation 61. The electrical conductors may comprise thesame or different conductors for connecting to each of theelectrosurgical electrode 18, radial wires 20, and side-cuttingelectrode 28. For example, in an embodiment of the present inventionwherein the electrosurgical electrode 18 and the radial wires 20 receiveRF power at a frequency of 0.8 MHz, and the side-cutting electrode 28receives RF power at a frequency of 5 MHz, conductors 58A, 58B and 60would separately provide 0.8 MHz RF power to the electrosurgicalelectrode and radial wires and a conductor 32 would separately provide 5MHz RF power to the side-cutting electrode 28.

At least a portion of conductors 32, 58A, 58B, 59 and 60 may comprise aflexible wire, more particularly conductors 58A and 58B connecting theanchoring mechanism or ablating mechanism, e.g. radial wires 20,conductor 32 and optionally push bar 59 connecting side-cuttingelectrode 28 to the RF power source 34. Flexible wire conductors areable to maintain electrical contact as the elongated shaft 14 isrotated, and as the anchoring mechanism or ablating mechanism (shownhere as radial wires 20) and side-cutting electrode 28 are deployed. Ina preferred embodiment, conductors such as 32, 58A, 58B, 59 and 60 areadapted to carry RF power efficiently by impedance matching, lowcapacitance, or other electronic design feature known in the art.

System 10 of the invention may be assembled by assembly of theconstituent parts, comprising wand 110, surgeon's disposable unit 120,and motor unit 130. As illustrated in FIG. 7, surgeon's disposable unit120 and motor unit 130 snap together to form a mechanically stable unitwhereby motive power may be transferred from motor unit 130 to surgeon'sdisposable unit 120. In preferred embodiments, the motive power isrotary power, with coupling between motor unit 130 and surgeon'sdisposable unit 120 provided by a shaft rotation assembly. In preferredembodiments, the shaft rotation assembly comprises a female part, suchas a ridged sleeve 77 in motor unit 130, operably coupled to a motor orother source of rotary power, and a male part, such as spindle 78. Inpreferred embodiments, ridged sleeve 77 is adapted to receive spindle 78effective to transfer rotary motion from ridged sleeve 77 to spindle 78.

As illustrated in FIG. 7, which provides perspective views of devices ofthe invention, surgeon's disposable unit 120 and the motor unit 130 snaptogether to form an effective unit where the surgeon's disposable 120 isoperably connected to the motor unit 130, as shown in FIG. 7B. Assemblyof the complete system 10 is effected by opening lid 66 and seating wand110 in receptacle 65 within surgeon's disposable unit 120 (as shown inFIG. 7 illustrating the positions of the elements just prior to seatingwand 110). Electrical connection is provided between wand 110 and RFpower source 34 by means of electrical connector 68 in receptacle 65 ofsurgeon's disposable unit 120, while mechanical power is provided towand 110 via shaft connector 70 within receptacle 65 of surgeon'sdisposable unit 120.

The assembled system 10 is shown in FIG. 8A, where shaft 14 extends outof surgeon's disposable unit 120, the rest of wand 110 being capturedwithin receptacle 65 of surgeon's disposable unit 120, not shown in FIG.8A because it is covered by lid 66. The system 10 is shown with radialwires 20 deployed in FIG. 8A; FIG. 8B shows the placement of electrodeshuttles 44 (side-cutting electrode shuttle), and 42A and 42 B (radialwire shuttles) and drive elements 74 (side-cutting electrode shuttleclasp) and 76A and 76B (radial wire shuttle clasps) for thecorresponding configuration of the device illustrated in FIG. 8A. Clasps74, 76A and 76B engage shuttles 44, 42A, and 42B respectively asillustrated in FIG. 8A and are effective to move the shuttles 44, 42A,and 42B longitudinally to deploy or retract side-cutting electrode 28and radial wires 20. It will be understood that the drive elements 74,76A and 76B will assume different positions, corresponding to theconfigurations of the electrode shuttles 42A, 42B, and 44 shown in theFigures, in order to move the electrode shuttles 42A, 42B, and 44 so asto effect the deployment or retraction of side-cutting electrode 28 andradial wires 20.

The positions of the shuttles 44 (side-cutting electrode shuttle), and42A and 42 B (radial wire shuttles) in the different configurations ofelectrode deployment are shown in FIGS. 8C-8F. The positions of thedrive elements 74 (side-cutting electrode shuttle clasp) and 76A and 76B(radial wire shuttle clasps) also shown in these configurations,correspond to the positions of the shuttles since the shuttle-claspdrive elements engage the electrode shuttles at all times while the wand110 is mounted within surgeon's disposable unit 120.

The positions of electrode shuttles 44, 42A and 42B and shuttle clasps74, 76A and 76B are shown in FIG. 8C for the configuration in which theside-cutting electrode and the radial wire electrodes are retracted.Separation of the radial wire electrode shuttles 42A and 42B, asindicated by the arrows in FIGS. 8C and 8D, is effective to deploy theradial wire electrodes 20 as illustrated in FIG. 8D. Such separation maybe effected by separation of the radial wire electrode shuttle clasps76A and 76B as shown in FIG. 8D.

Deployment of the side-cutting electrode 28, as illustrated in FIG. 8E,is effected by longitudinal movement of the side-cutting electrodeshuttle 44, as indicated by the arrow near to side-cutting electrodeshuttle 44 in FIG. 8E. Deployment of the side-cutting electrode 28itself is indicated in FIG. 8E by the radial arrow shown pointing to thedeployed side-cutting electrode 28; such deployment may be effected bylongitudinal movement of side-cutting electrode shuttle clasp 74 asshown in FIG. 8E. It will be understood that retraction of theside-cutting electrode 28 may be effected by movement of theside-cutting electrode shuttle clasp 74 and side-cutting electrodeshuttle 44 in the opposite direction.

Retraction of the radial wire electrodes 20 is effected by movementtogether of the radial wire electrode shuttles 42A and 42B, asillustrated in FIG. 8F, with arrows indicating the direction of movementthat resulted in the final position of the radial wire electrode shuttleclasps 76A and 76B and radial wire electrode shuttles 42A and 42B shownin the figure. Longitudinal arrows near the radial wire electrodes 20indicate the direction of movement of the radial wire electrodesthemselves during retraction.

Thus, in preferred embodiments, the deployment and retraction of radialwires 20 and of side-cutting electrode 28 may be effected by themechanisms illustrated in FIG. 8. When seated in receptacle 65, wand 110is placed so as to engage side-cutting electrode shuttle 44 withside-cutting electrode shuttle clasp 74, and radial wire shuttles 42Aand 42B are placed so as to engage radial wire shuttle clasps 76A and76B. Note that when side-cutting electrode 28 is retracted as in FIGS.8A-8D; side-cutting electrode shuttle clasp 74 is positioned away fromdrive gear 72, in the most proximal position along its range of motion.In FIGS. 8E and 8F, the side-cutting electrode 28 is deployed. In thisconfiguration side-cutting electrode shuttle clasp 74 is in its mostdistal position. Movement of side-cutting electrode shuttle clasp 74 ina distal direction, when engaged with side-cutting electrode shuttle 44,is effective to deploy side-cutting electrode 28.

Similarly, radial wires 20 are shown deployed in FIGS. 8A and 8D, andretracted in FIG. 8C. In this configuration, radial wire shuttle clasps76A and 76B are laterally displaced from each other, as shown in FIG.8B. When engaged with radial shuttles 42A and 42B, radial shuttle clasps76A and 76B are effective to deploy radial wires 20 when positionedlateral from a medial position at which the radial wires 20 areretracted.

Shaft 14 may be rotated by rotation of drive gear 72 which is operablyengaged with shaft gear 41. When such rotation is effected whileside-cutting electrode 28 is deployed and conducting RF power into apatient's tissues, a swath of tissue will be cut or ablated. Inpreferred embodiments, the rotary motion comprises at least 360°, or acomplete circle, effective to completely isolate a body of tissue withinthe patient's body. In most preferred embodiments, the rotary motioncomprises at least 360° plus about 45°, or about 405°, effective tocompletely isolate a body of tissue within the patient's body and toleave the side-cutting electrode 28 in a position that is not above theslot in the tissue that is formed by deployment of the side-cuttingelectrode 28. Removal of such an isolated body of tissue then provides abiopsy specimen or may comprise a surgical procedure, such as alumpectomy. Referring to FIG. 8, the system 10 is shown ready to begin aprocedure in FIG. 8A, with shaft 14 anchored in position in a patient'sbody by radial wires 20. Retraction of radial wires 20, and deploymentof side-cutting electrode 28, preferably with RF power supplied toside-cutting electrode 28, is shown in FIG. 8F. Retraction of radialwires 20 facilitates rotation of shaft 14 and aids cutting byside-cutting electrode 28. hen shaft 14 is in place within a patient'sbody, rotation of shaft 14 with side-cutting electrode deployed andsupplied with RF power is effective to cut and isolate a body of tissuewithin a patient's body. Following such cutting and isolation of tissue,side-cutting wire 28 may be retracted and radial wires 20 redeployed, asin the configuration shown in FIG. 8D, fixing the isolated body oftissue to shaft 14 for removal of the body of tissue when shaft 14 isremoved from the patient.

An illustration of a portion of the device positioned within the body ofa patient is provided in FIG. 9. In preferred embodiments, the inventionwill be used to perform biopsies, lumpectomies, and other procedures onthe breast tissue of patients. FIG. 9 shows a cross-sectional view of abreast 80 of a patient undergoing a clinical procedure comprising anembodiment of a method of the invention, showing a portion of a shaft 14with an electrosurgical electrode 18 at the distal tip. The shaft 14 hasbeen inserted in the breast 80 through an incision 82 in the surface ofthe breast 80, along a path 84 created by action of the electrosurgicalelectrode 18 under the guidance of an operator, such as a surgeon. Priorto the configuration illustrated in FIG. 9, radial wires 20 had beendeployed to anchor the wand 110 in a desired location, then had beenretracted prior to rotation of shaft 14. Next, side-cutting electrode28, shown here in its deployed configuration, was used to make aboundary cut 86 within the breast 80 of the patient, effective toisolate a body of tissue 88 within the boundary cut 86. The isolatedtissue is fixed in position around shaft 14 by radial wires 20, whichwere preferably redeployed after side-cutting electrode 28 made boundarycut 86. In preferred embodiments, the side-cutting electrode 28 wouldnext be at least partially retracted, while the radial wires 20 remaindeployed with isolated tissue 88 attached to the radial wires 20.Removal of the device by pulling the device back along path 84 iseffective to remove isolated tissue 88.

FIG. 10 illustrates rotation of the shaft 14 and side-cutting electrode28 during isolation of a body of tissue within a patient's body. FIGS.10A, 10B, and 10C illustrate transverse cross-sections taken along lineC-C depicted in FIG. 10D, which is a partially cut-away cross-sectionalview of a wand 110 of the invention. As illustrated in FIG. 10A,side-cutting electrode 28 has been deployed, and radial wire electrodes20 have been retracted. Rotation of shaft 14 and side-cutting electrode28 around a longitudinal axis of the shaft 14 is indicated by the curvedarrow in FIG. 10A. FIG. 10B depicts the position of the shaft 14 andside-cutting electrode 28 after a full rotation with RF power suppliedto the side-cutting electrode 28. The body of target tissue 88 has beenisolated from surrounding body tissue by boundary cut 86 formed by thepassage of the side-cutting electrode 28 in the direction indicated bythe curved arrow. Note that shaft 14 and side-cutting electrode 28 haverotated more than a full circle, through greater than 360°, leavingside-cutting electrode in a position away from the radial cut made asthe side-cutting electrode 28 was deployed. Following formation ofboundary cut 86 effective to isolate body of tissue 88, RF power wassupplied to radial wire electrodes 20 which are deployed as shown inFIG. 8C in order to fix body of tissue 88 in position along the shaft.The position of radial wire shuttles 42A and 42B in this configurationis shown in FIG. 10D, with longitudinal arrows indicating the directionof travel of radial wire shuttles 42A and 42B. In addition, RF power isshut-off from side-cutting electrode 28 at this point; and it may beretracted, partially or completely, as illustrated in FIG. 10C, to aidin fixing the body of tissue 88 to the shaft; alternatively,side-cutting electrode may be left deployed. With body of tissue 88fixed to shaft 14 by radial wire electrodes 20 and optionally byside-cutting electrode 28, the body of tissue 88 may be withdrawn fromthe patient's body.

The devices of the invention, when inserted into a patient's tissue atthe appropriate position, provide access to a desired site or a targettissue site under examination. The pathway produced in reaching thedesired site in the patient's tissues, provides access for directingfluid, gel, paste, chemicals, drugs, markers, or other fluid orsemifluid material to the region of the patient's body. Devices of theinvention may themselves provide means to introduce markers, chemicals,drugs, fluids or other objects to the desired site in the patient. U.S.patent application Ser. No. 09/343,975 (assigned to the assignee of thepresent application and herein incorporated by reference in itsentirety) describes the use of such temporary and permanent markers, andits disclosure is incorporated herein by reference. For example, asurgical dye may be injected along the elongated shaft 14 or a surgicaldye may be injected through a bore provided in shaft 14 to mark theregion and to provide a guide for subsequent surgical procedures. Also,hemostatic agents (such as those that contain fibrin or afibrin/fibrinogen mixture) may be introduced along the elongated shaft14 or through a bore provided in shaft 14 to stem bleeding that mayoccur during a biopsy procedure.

The use of devices of the invention, and methods for accessing tissue ata desired site within a patient and isolating a body of target tissue,methods for performing a biopsy, and methods for performing alumpectomy, are provided in more detail in the following paragraphs.

Typically, an incision is first made (e.g., with a conventional scalpel)through the patient's skin. With RF power supplied to theelectrosurgical electrode 18, the electrosurgical electrode 18 and thedistal tip 12 of the wand 110 are inserted into the incision. Inaccordance with the use of conventional electrosurgical apparatus, theoperator activates an electrosurgical generator (such as the source ofRF power 34) using a control switch (not shown), such as a foot pedal,to apply high frequency electrical energy to the electrosurgicalelectrode 18. In embodiments of the invention, the electrosurgicalgenerator can operate at about 100 KHz (0.1 MHz) to about 10 MHz. In oneembodiment of the invention, the electrosurgical generator can operateat about 300 KHz to about 1500 KHz (1.5 MHz), specifically, at about 600KHz to about 1000 KHz (1 MHz), most preferably about 800 KHz (0.8 MHz).Power output for such an electrosurgical generator can be about 50 toabout 150 watts, preferably, about 80 to about 100 watts. Where tissuecoagulation is desired, greater amounts of power output may be supplied,and/or the waveform may be changed, and/or the voltage increased. As theelectrosurgical electrode 18 contacts the tissue, the contacted tissueis ablated, allowing insertion of the electrosurgical electrode 18 andshaft 14 through the tissue without deforming or displacing tissue it ispassing through.

The electrosurgical electrode 18 makes a passage through the tissue thatpermits shaft 14 to be readily inserted, providing a suitable passagethrough the tissue without pushing tissue aside or displacing targettissue as it advances. The electrosurgical ablation process is continueduntil the electrosurgical electrode 18 and shaft 14 are appropriatelypositioned with regard to the desired site within the patient's body.Once in place, the electrosurgical electrode 18 and shaft 14 provideaccess to the desired site within the patient's body.

In order to prevent movement of shaft 14 after placement in the desiredsite within the patient's body, radial wires 20 may be extended,penetrating tissue in a generally radial direction away from shaft 14 ofthe wand 110. The radial wires 20 penetrate into the tissue as theyextend, and are effective to prevent undesired movement and to anchorshaft 14 in place. It will be understood by those of skill in the artthat wires, such as radial wires 20, will readily penetrate into apatient's tissues without displacing or deforming surrounding tissues.In a preferred embodiment, RF power is supplied to the radial wires 20as they are extended, so that the radial wires 20 cut through apatient's tissues quite readily so as to penetrate into a patient'stissues without displacing or deforming surrounding tissues. Inaccordance with the use of conventional electrosurgical apparatus, theoperator activates an electrosurgical generator (such as the source ofRF power 34) using a control switch (not shown), such as a foot pedal,to apply high frequency electrical energy to the radial wires 20. Inembodiments of the invention, the electrosurgical generator can operateat about 100 KHz (0.1 MHz) to about 10 MHz. In one embodiment of theinvention, the electrosurgical generator (such as RF power source 34)can operate at about 300 KHz to about 1500 KHz (1.5 MHz), specifically,about 600 KHz to about 1000 KHz (1 MHz), most preferably about 800 KHz(0.8 MHz). Power output for such an electrosurgical generator can beabout 50 to about 150 watts, preferably, about 80 to about 100 watts.Where tissue coagulation is desired, greater amounts of power output maybe supplied. As the radial wires 20 contact the tissue, the contactedtissue is ablated, allowing extension of the radial wires 20 through thetissue without causing undesired motion of the wand 110 and withoutdeforming or displacing the surrounding tissue. In the extendedconfiguration, the radial wires 20 anchor the electrosurgical system 10into place, preventing motion or displacement from the desired site. Ascan be seen from the two depictions of the radial wires 20 in FIG. 4,the amount of extension of the radial wires 20 may vary, eitherdepending upon their intended use (as anchor wires or as ablation wires,for example) or the extent of deployment may be controlled as desired bythe operator, with movement of the radial wires 20 effected by action ofdeployment shafts 58A and 58B. The radial wires may be completely housedwithin shaft 14, as is desirable, for example, during the initialinsertion of wand 110 and passage through the tissues of the patientbefore arrival at the final desired site within the patient's body.

In preferred embodiments, side-cutting electrode 28 lies along shaft 14when not deployed. In alternative embodiments, side-cutting electrode 28may be housed in shaft 14, and of being extended in a substantiallyradial direction to deploy from a slot to form an arcuate electrode.

During deployment of the side-cutting electrode 28, RF power may besupplied to the side-cutting electrode 28 to facilitate its travelthrough the patient's tissues. In accordance with the use ofconventional electrosurgical apparatus, the operator activates anelectrosurgical generator (such as the source of RF power 34) using acontrol switch (not shown), such as a foot pedal, to apply highfrequency electrical energy to the side-cutting electrode 28. Inembodiments of the invention, the electrosurgical generator can operateat about 100 KHz (0.1 MHz) to about 10 MHz. In one embodiment of theinvention, the RF power source 34 can operate at about 500 KHz to about10,000 KHz (10 MHz), preferably, about 2500 KHz to about 7500 KHz (about2.5 MHz to about 7.5 MHz), most preferably about 5000 KHz (5 MHz). Poweroutput for such an electrosurgical generator can be about 100 to about1000 watts, preferably, about 120 to about 500 watts. Where tissuecauterization is desired, greater amounts of power output may besupplied. As the side-cutting electrode 28 contacts the tissue, thecontacted tissue is ablated, allowing extension of the side-cuttingelectrode 28 through the tissue without causing undesired motion of theshaft 14 or of wand 110 and without deforming or displacing thesurrounding tissue. The side-cutting electrode 28 is effective to cuttissue and also to cauterize tissue when a suitable amount of RF poweris supplied to the side-cutting electrode 28.

The side-cutting electrode 28 may be used to cut a path through tissueeffective to isolate a portion of the body tissue of a patient. When theshaft 14 is in a desired site within a patient's body, tissue that isthe object of interest, such as tissue to be taken for a biopsy sample,is located adjacent or near to shaft 14. The side-cutting electrode 28may be deployed to a variable extent, that is, to a greater or lessermaximal radial distance from shaft 14 as desired by the operator. Adesired maximal radial distance is one where the radius of the arc ofthe side-cutting electrode 28 is greater than the distance of the tissueof interest from shaft 14, and, when rotated around longitudinal axis24, defines a shape that is substantially a spheroid enclosing thetissue of interest. Application of RF power to the side-cuttingelectrode 28, retraction of the radial wires 20 and rotation of theside-cutting electrode 28 around longitudinal axis 24 is effective tocut a substantially spherical or ellipsoidal passageway to form boundarycut 86 through a portion of the patient's body tissue. Such rotation ofthe side-cutting electrode 28 around longitudinal axis 24 while theside-cutting electrode 28 is deployed and connected to and receiving RFpower, with radial wires 20 retracted, is effective to provide boundarycut 86 within the patient's body, effective to isolate the tissue ofinterest 88 from body tissue that is located farther from shaft 14 thanthe side-cutting electrode 28. The power supplied to the side-cuttingelectrode 28 may be sufficient to cut tissue or greater power may beused effective to coagulate the tissue adjacent boundary cut 86 that iscut by the side-cutting electrode 28. As disclosed above, preferred RFpower for the side-cutting electrode 28 is supplied by RF power source34 preferably at a frequency of about 5 MHz, although RF power in afrequency range of between about 2.5 MHz to about 7.5 MHz, and in arange of between about 0.1 MHz to about 10 MHz is also within the scopeof the invention.

In addition to wand 110, surgeon's disposable unit 120, motor unit 130,and manual handle 140, the invention comprises methods of accessingtarget tissue, and of isolating tissue, of performing a biopsy on targettissue at a desired site within a patient, and of performing alumpectomy on a breast of a patient.

A method of accessing target tissue at a desired site within a patient'sbody comprises providing an electrosurgical device or wand 110,positioning the electrosurgical electrode 18 of the device 110 incontact with the patient's body, supplying high frequency electricalcurrent to the electrosurgical electrode 18 while advancing the distalend 16 of the device 110 into the patient and through the site of targettissue, expanding the elongated members of an anchoring mechanism(preferably radial wires 20) to penetrate the surface of the targettissue in order to fix the device 110 with respect to the target tissuesite, expanding the cutting element of the side-cutting mechanism 28into the target tissue, and rotating the cutting element of theside-cutting mechanism 28 about a longitudinal axis 24 of shaft 14 ofthe device 110 to form a body of target tissue 88. In one embodiment ofthe method, the skin of the patient may be first cut to exposesubcutaneous tissue before supplying high frequency electrical currentto the electrosurgical electrode 18 while the electrosurgical electrode18 is advanced through the tissue of the patient.

A method of performing a biopsy on target tissue at a desired sitewithin a patient comprises providing a device 110 of the invention,positioning the electrosurgical electrode 18 in contact with thepatient's body, supplying high frequency electrical current to theelectrosurgical electrode 18 while advancing the distal end 16 of thedevice 110 into the patient and through the site of target tissue,expanding the elongated members of the anchoring mechanism, such asradial wires 20, to penetrate the surface of the target tissue in orderto fix the device with respect to the target tissue site, expanding thecutting element of the side-cutting electrode 28 into the target tissue,rotating the cutting element of the side-cutting electrode 28 about alongitudinal axis 24 of the shaft 14 of the device 110 to form a body oftarget tissue 88, and withdrawing the biopsy device 110 with the body oftarget tissue 88 from the patient.

A method of performing a lumpectomy on a breast of a patient comprisesproviding a device of the invention 110, positioning the electrosurgicalelectrode 18 of the device 110 in contact with the patient's breasttissue, supplying high frequency electrical current to theelectrosurgical electrode 18 while advancing the distal end 16 of thedevice 110 into the patient's breast tissue and through the site oftarget tissue, expanding the elongated members of the anchoringmechanism, such as radial wires 20, to penetrate the surface of thetarget tissue in order to fix the device with respect to the targettissue site, expanding the side-cutting electrode 28 of the side-cuttingmechanism into the target tissue, rotating the side-cutting electrode 28of the side-cutting mechanism about a longitudinal axis 24 of shaft 14of the device 110 to form a body of target tissue 88, and withdrawingthe device 110 and the body of target tissue 88 from the patient'sbreast.

In the practice of these methods, including the method of performing abiopsy on target tissue at a desired site within a patient and themethod of performing a lumpectomy on a breast of a patient, theelectrical current supplied to the electrosurgical electrode may be at afrequency of about 0.1 MHz to about 10 MHz; more preferably about 0.3 toabout 1.5 MHz, and most preferably at a frequency of about 0.8 MHz. Theelongated members of the anchoring mechanism, such as radial wires 20,may be formed of electrically conducting material and high frequencyelectrical current is preferably supplied to the elongated members ofthe anchoring mechanism while they penetrate the surface of the targettissue. In the practice of the methods, the electrical current suppliedto the radial wires 20 may be at a frequency of about 0.1 MHz to about10 MHz; more preferably about 0.3 to about 1.5 MHz, and most preferablyat a frequency of about 0.8 MHz. The electrical current supplied to theside-cutting electrode 28 of the side-cutting mechanism may be suppliedat a frequency greater than the frequency of the electrical currentsupplied to the electrosurgical electrode 18. In the practice of themethods, the electrical current supplied to elongated electrode of theside-cutting mechanism 28 may be at a frequency of about 0.1 MHz toabout 10 MHz; more preferably about 2.5 to about 7.5 MHz, and mostpreferably at a frequency of about 5 MHz. The side-cutting electrode 28of the side-cutting mechanism may be expanded to an arcuate shape thatupon rotation about the axis 24 of the shaft 14 is effective to isolatea body of target tissue 88 that is spherical or substantially spherical.Following isolation of the target tissue 88, the radial wires 20 mayagain be deployed, fixing the target tissue 88 to the device 110effective to remove the target tissue 88 along with the removal of thedevice 110 from the patient's body.

In a further embodiment of the invention, the shaft 14 of wand 110 maybe withdrawn from the passage 84 that provides access to the desiredsite in the patient's body, and another device inserted into thepassage. For example, a biopsy device may be inserted along the passage84 to remove a biopsy sample. A biopsy device may be advantageously ofthe type described in U.S. Pat. Nos. 5,526,822; 5,649,547; 5,775,333;and 5,928,164, the disclosures of which are incorporated herein byreference. In preferred embodiments of the method in which a biopsydevice is inserted along the passage, a biopsy device such as aMammotome® with a sampling chamber, is inserted into the passage, sothat the sampling chamber is aligned with the target tissue, until thesampling chamber of the biopsy device is exposed within the targettissue mass 88 and the biopsy sample taken. Alternatively, the wand 110may comprise a biopsy device.

In addition, it is often desirable to place markers to identify thelocation from which biopsy samples were taken. The methods disclosedherein contemplate the use of such markers in conjunction andcombination with other methods of the invention for accessing targettissue at a desired site within a patient and isolating a body of targettissue, for performing a biopsy on target tissue at a desired sitewithin a patient, and for performing a lumpectomy on a breast of apatient. If tests on the sample indicate that surgery is called for toremove tissue from the biopsy site, the markers identify the location ofthe site using x-rays, ultrasound, or other imaging techniques, topermit the surgeon to remove the appropriate tissue. In some instances,it may be desirable to mark the location from which the biopsy sampleswere taken with a permanent marker. This may be appropriate when theexamination determines that the tissue taken at the biopsy site wasbenign. Doctors may find it helpful to identify in subsequentexaminations of the patient that the suspect tissue mass has previouslybeen examined, and determined not to require further biopsy. Locationmarkers for such purposes are typically permanent, but they mayalternatively be temporary, designed to be absorbed into the body in afew weeks to a few months. Permanent markers may include metal clipsthat are visible with x-rays. Temporary markers may be formed of abiocompatible, radio-opaque gel that is absorbed over time in the bodytissue. Both temporary and permanent markers are described in previouslynoted U.S. patent application Ser. No. 09/343,975, filed Jun. 30, 1999.

A marker insertion device for placing such markers may be guided throughpassage 84 created by wand 110 and used to install a permanent marker,such as, for example, a metal clip. Other devices or materials may beinserted into or through the passageway created by the use of wand 110.For example, a surgical dye and/or a hemostatic agent may be injected,as discussed above, or a coagulation device, such as the electrosurgicalunit, may be inserted.

At the conclusion of all procedures requiring access to the desired sitewithin a patient's body and the tissue surrounding it, the wand 110 maybe removed from the patient's tissue, or, if another device or deviceshave been inserted into the passage 84 created by wand 110 after removalof wand 110, these devices are removed. The incision is thenappropriately closed.

Those skilled in the art will recognize that various modifications maybe made to the specific embodiments illustrated above without departingfrom the spirit of the present invention. For example, it will beunderstood that although radial wires 20 and side-cutting electrode 28comprise preferred embodiments of anchoring mechanisms and side-cuttingmechanisms of the invention, the invention is not intended to be limitedto these embodiments alone, but to include variants and alternativeembodiments as well, as one of ordinary skill in the art will appreciatethat other embodiments of the anchoring mechanism and side-cuttingmechanism, including alternative shapes of these elements, are alsosuitable for the practice of the invention. Such alternative embodimentsof, for example, anchoring devices, may include hooks, barbs, fins,glues, and other means suitable to serve as an anchoring mechanism andare within the scope of the invention.

In addition, it will be recognized that additional steps may be added tothe procedure described above, depending on the specific needs of thepatient. These and other modifications that may suggest themselves areconsidered to be within the spirit and scope of the invention, asdefined in the claims that follow.

1. A system for accessing target tissue within a patient and isolating abody of target tissue from its supporting bed, comprising a. a biopsydevice having a wand with a proximal portion and a distal portion, ahousing on the proximal portion, an electrosurgical tissue cuttingelectrode secured to the distal portion of the wand, a first electricalconductor extending within the wand having a distal end electricallyconnected to the electrosurgical electrode and a proximal end configuredto be electrically connected to an electrical power source, at least onedeployable tissue contacting element connected to said distal wandportion and at least one driving member within the housing configured tomove at least one deployable tissue contacting element of the biopsydevice; b. a replaceable drive unit having a receptacle for engaging andreleasably holding at least a portion of the housing on the proximalportion of the wand, and a driving element configured to engage the atleast one driving member within the housing configured to transfermechanical power to said biopsy device; and d. a motor unit for engagingand providing power to the driving element of the drive unit, comprisinga securing mechanism effective to form a mechanically stable engagementbetween said motor unit and said drive element of the driving unit totransfer mechanical power therebetween.
 2. The system of claim 1,wherein said at least one deployable element is a side-cutting element.3. The system of claim 2, wherein the wand has a distal end and saidside-cutting element is located proximal to the distal end of the wand.4. The system of claim 3, wherein said side-cutting mechanism isconfigured to be rotated about a longitudinal axis of the wand toisolate a body of target tissue when said wand is disposed within apatient.
 5. The system of claim 2, wherein said tissue anchoringmechanism comprises a radially extending wire.
 6. The system of claim 2,wherein said anchoring mechanism of said biopsy device includes aplurality of elongated members configured to expand outwardly from thewand and to penetrate into target tissue.
 7. The system of claim 6wherein said elongated members of said anchoring mechanism are formed atleast in part of electrically conducting material.
 8. The system ofclaim 7 wherein a third electrical conductor extends within theelongated shaft of the biopsy device and has a distal end electricallyconnected to at least one of the elongated members and a proximal endconfigured to be electrically connected to an electrical power source.9. The system of claim 7 wherein the elongated members of said anchoringmechanism are metallic wires or ribbons.
 10. The system of claim 7wherein the wires or ribbons are movably mounted to the wand of thebiopsy device and have a contracted configuration to facilitateadvancement of the biopsy device within the patient and a radiallyexpanded configuration to penetrate into target tissue.
 11. The systemof claim 1 wherein the at least one deployable element is an anchoringmechanism which is configured to be extended into the body of targettissue when said wand is disposed within a patient.
 12. The system ofclaim 11, including a side-cutting mechanism comprising an elongatedelectrode having a distal end secured distal to the anchoringmechanisms, a proximal end secured proximal to the anchoring mechanismand a second electrical conductor extending within the wand having adistal end electrically connected to the elongated electrode and aproximal end configured to be electrically connected to an electricalpower source.
 13. The system of claim 1, wherein the drive element ofsaid drive unit is configured to engage a shuttle effective to deploy orretract the deployable element of said biopsy device.
 14. The system ofclaim 1, wherein said drive unit further comprises a drive gearconfigured to engage a shaft gear effective to rotate said wand.
 15. Thesystem of claim 1, wherein said drive unit has a mechanical connectorcomprising a spindle, and wherein said transferred mechanical powercomprises rotary power.
 16. The system of claim 1, wherein said securingmechanism of said motor unit comprises a releasable connection.
 17. Thesystem of claim 1, wherein said mechanical power of said motor unitcomprises rotary power and said securing mechanism comprises a ridgedsleeve configured to receive a spindle effective to transfer rotarymotion.
 18. The system of claim 1, wherein said electrosurgicalelectrode of said biopsy device has a cutting surface spaced distal tothe distal end of the shaft.
 19. A system for severing a tissue bodywithin a patient from supporting tissue, comprising: a. a tissuesevering unit having an elongated wand with a tissue cutting element ona distal portion of the wand, an additional operative element on thedistal portion of the wand and a housing on a proximal portion of thewand and moving elements within the housing for moving the tissuecutting element and the additional operative element; b. a replaceabledrive unit having a recess for receiving at least a portion of thehousing of the tissue severing unit and having driving elements forengaging moving elements within the housing of the tissue severing unitto operate the tissue cutting element and the additional operativeelement on the distal portion of the wand; and c. a motor unit having amotor, a mechanical connector configured to transfer mechanical powerfrom the motor to the driving elements of the drive unit to operate thetissue severing element and to operate the additional operative elementof the tissue severing unit.
 20. The system of claim 19 including asecuring mechanism effective to form a mechanically stable engagementbetween the motor unit and the drive unit, and a coupling mechanismconfigured to engage with the mechanical connector of the motor uniteffective to transfer mechanical power.
 21. The system of claim 20wherein the mechanical power is rotational power.
 22. The system ofclaim 19, wherein the drive unit is configured to engage a shuttleoperably connected to a moving member in the housing of the tissuesevering unit to operate an operative element on the distal portion ofthe wand.
 23. The system of claim 22, wherein the drive unit includes adrive gear configured to engage a moving member within the housing ofthe tissue severing unit.
 24. The system of claim 23 wherein the movingmember is a shaft gear that is effective to rotate the wand of thetissue severing unit.
 25. The system of claim 19, wherein the tissuecutting element is a radially deployable cutting element.
 26. The systemof claim 25 wherein the deployable cutting element is an electrosurgicalcutting element.
 27. The system of claim 19 wherein the mechanicalconnector includes a spindle.